1. Field of the Invention
The present invention relates to an image forming system including an image forming apparatus and a computer or other terminal coupled to the apparatus. In particular, the invention relates to such an image forming system that checks authentication information input from the terminal to grant an authorized user a setting change for the image forming apparatus.
2. Related Art
When an unspecified number of people share a single printer and each one of them has access to change its default settings, they may not be able to get their documents printed just as they expected. For example, when a user who wants one-sided printing and gets his document printed with a printer without knowing another user has just set two-sided printing for the printer, this user will end up having a bunch of two-sided prints. Another concern about sharing a printer between two or more users, each of who can change its settings, is leakage of data stored therein.
To cope with these problems, an image forming apparatus (printer) typically has a user authentication mode for granting only authorized users the authority to change the default settings among those who have registered to use the printer.
The user authentication mode, however, involves another problem. When the mode is working, the terminal coupled to the printer sends user information such as a user ID and password every time the user tries to change the settings for the printer. Then, only if the user is deemed to have authority to make a change, the terminal sends the setting change to the printer. If the user wants to make multiple changes in the printer settings, this authentication is repeated every time the user tries to send a setting change. Therefore, it takes quite a long time to complete the setting change through time-consuming means of communications such as local connections.
For example, Japanese Patent Laid-Open Publication No. JP-2004-133906-A discloses an image forming apparatus, a use authentication information issue method, and a use authentication information issue system capable of reducing an unnecessary authentication process for certain services provided by the image forming apparatus (compound machine) with printer, fax, and copier functions etc. involving password authentication and used repeatedly.
When the image forming apparatus disclosed in JP-2004-133906-A receives a session establishment request including authentication information from external network equipment, the apparatus executes an authentication process on the basis of the session establishment request, generates session information and session identification information, and transmits the information to the network equipment. When receiving a prescribed processing request using the session identification information from the network equipment, the image forming apparatus decides the session information corresponding to the session identification information, and executes the prescribed processing request received from the network equipment according to contents of the session information.
Using the session identification information in this manner can eliminate the need to repeat the authentication process when processing is deemed to be executed by the same session. It is therefore possible to avoid redundancy in the authentication process.
Since the session identification information used in JP-2004-133906-A includes the IP addresses of the network equipment executing a processing request and of the image forming apparatus having a session established as well as a term of validity, the information may be abused by a third party. Moreover, JP-2004-133906-A does not disclose the use of an authentication key as the session identification information so as to grant only authorized users specific processing.